1. Field of the Invention
This invention relates to an electronic ringing circuit. More specifically, the invention relates to such a ringing circuit which includes means for providing a plurality of ringing frequencies, and further means for shifting from one ringing frequency to another.
2. Description of the Prior Art
The ringing circuit of present day telephones consist mainly of mechanical devices activated by an electrical ringing circuit signal coming over the telephone lines. However, telephones are becoming more and more electronic, and it is, therefore, useful to have an electronic circuit for providing the ringing signal.
In addition, present day telephones provide a jarring note mostly at one frequency. Electronic ringing circuits can provide a pleasant sound with a futuristic ring having a plurality of ringing tones.